.pps is not a spreadsheet, it is a Microsoft powerpoint presentation and usually run in conjunction with Word. You may have to use OpenOffice or something similar to display it, as I am not sure if your version of Lotus will support the format.
Surface Pro (2017) vs Surface Pro 4
20 groundbreaking 3D animation technologies coming to Siggraph 2017
iPad Pro 12.9 vs Surface Pro 5
Synology invites you to visit them at Insomnia on 26th – 29th August. Book your tickets now and visit Synology.